Phosphate reducer for bottom chrome dyeing



Patented July 3, 192s.

UNITED STATES.

1 1 45 PATENT OFFICE.

m NEVILLE, OI BIBHINGHAM AL ABA IA, ASSIGNOB '1O I'EDERAL PHOBPHOBUB comm, BIRMINGHAM, ALABAIA, A- CORPORATION 01 rnosrm'm mum ms nor 'rom canon: Drama.

Io Drawing.-

My invention relates to a new and improved chrome assistant in a mordanting bath for bottom chrome dyeing where bichromateof soda is to be used. I have dis- 6 covered that by the use of a phosphate, preferably in the form of acidsodium pyrophosphate, itLis possible to obtain an action on bl-chromate of soda when used for bottom chroming of wool. The pyro-phosphate 10 acts as achrome assistant, as is sometimes referred .to'by operators of bottom chroming o operations, and as this action takes place in the mordant bath," the bi-chromate is reduced "to lower oxides of chromium-without allowing it to be deposited on the wool fiber in the form of higher oxides, chromium chromate,

or chromium hydroxide.

My object is to produce brighter colors from correspondingy roportional quantities of dye when pyro-p osphates are used as assistants, than is-possible when lactic or tar- .taric'acid salts are used for such purpose. A further object is to reduce the c'ost of the dyeing operation by the substitution of acid ,taric acid salts. Heretofore it has been sodium pyro-phosphate for'lacticand terthe practice to use organic assistants for bottom chrome dyeing,"

where the bi-chromate is reduced to lower so oxides before deposition on the fiber. The

salts of lactic and tartaric acid arecommonly used, as well as numerous mixtures. containsalts of these acids, as active ingredients;

ince there are many combinations of dyeants and varying results ma be obtained,

those that I will use areil ustrative, and

are not intended to limit the use of a phosphate', preferably sodium acidpyro-phosv 40 phate, except asspecified in my claims.

Many dye-stufis are very sensitive to the condition of the chrome on the fiber of the wool. The basis for the particular utilization of my process is thatthe bi-chromateof as soda is more perfectly reduced to the lower oxide, or that the sensitive dye-stufl's give brighter and more even colors onwool which in the mordant bath were chromed with bichromate and gc hos hate. Further,- I

have' observed t with certain dye-stuffs small quantities of pyro-pho sphate produce colors which muchbrighter than ob tained from larger quantities otthesame d e stufis whemother assistants are used. belief is supported by, comparison of Application fled 0 cm: 29,1924, Serial no. mma

wool which had been chromed using pure sodium acid pyro-phosphate with wool chromed by using half refined tartar. The wool from the. mordant bat-h using pyrophosphate showed a brighter shade for the skeins than'the wool from the morda-nt bath 1n which thebi-chromalte of soda was reduced with half refined tartar.

I believe the pyro-phosphate is converted to ym-phosphoric acid, and it is the action f t e yro-phosphoric acid which reduces the b1- romate. I have found'that bi-sul phate of soda when mixed with pyro-phosphate'will accelerate the action of the bichromate. The bi-sulphate of soda should be used preferably in quantities correspond- 1n% to the chemical uation.

ince some dye-stu s are best suited to the condition of the chromium oxide resulting from certain mordanting baths, they will produce more satisfactory colors than will other dyes using the same bath. For instance, anthracene blueBadische W. G. G. is typical of a d e which will reduce an improvement of s ade when use in connection with pyro-phosphate mordanting baths. Moreover, the increased brightness in color is obtained from it with less pyro-phosphate than if tartaric acid salts were used,and this leads me to believe that there may be some catalytic action of the pyro-phosphate in the chrome mordanting bath, or that some constituent in the wool is removed, which a results in a material brightening of the color.

as. stufis which maybe used with various assist- In order that my process may be illus-' trated, I will now give as an example the results'of tests illustrative'of yarious as sistants used in the mordanting bath in which the yarn was subsequently dyed with the various ,dye-stufis mentioned. White worsted yarn wastreated with weak ammoon' theweight of the wool treated, and in .addition'each bath contained percen f the different assistants, on the same i as f ll I a o. 2bathccii inedaanfassistant1i%% pure ar "ls-with'1 bi-sulphate of soda,

1 No. 3 ath contained asan assistant 154% no fully one hour thereafter. In the case ofpyro-phosphate with 1 4% bi-sulphate of soda Nd. 4' bath contained as an assistant 3% pure cream of tartar,

No. 5 bath contained as an assistant 3% pyro-phosphate of soda,

No. 6 bath contained as an assistant 3% Lactrozine,

No.' 7 bath contained as anassistant 3% pure commercial lactic acid (22%).

After the mordanting bath, the skeins were washed very thoroughly before dyeing, and each skein was then dyed-in a se arate beaker of which there were five, eac containing the dye-stuff in the percentage based on the wool dye,'as follows:

Beaker No. 1 alizarine brown B-powder calco-1%,

Beaker No. 2 anthracene blue W. G. G.- pasteextraBadische-4%,

Beaker No. 3 alizarine red-20% paste- Beaker No. 4 American dyewood logwoodfull oxidized-1%,

Beaker o. 5 American dyewood logwood oxidized1%. I

One skein for each mordanting bath used was dyed with each of the first three dyestuffs; while the skeins from the first five mordanting baths were dyed with the fourth dye-stuffs; and skeins from the mordanting baths No. '1 and N0. 5 were dyed with the fifth dye-stuff only. In all cases the dye baths were brought to a boil in one half hour and continued to boil for No. 1 dyestufi, it showed very little difierence, as all of the baths were practically exhausted after dyeing was completed. The

skeins of wool treated in the pyro-phosphate' mordanting baths seemed to exhaust the dye bath 'more quickly than those skeins treated in the other *mordanting baths.

-With the No. 2 dyestufi, the dye bath was not exhausted after dyeing; however, this is often true with this particular dye-stuff and accordingl no color comparison was made on the bat During the dyeing process it could be plainly seen that the skein from mordanting bath No. 5 produced a brighter color which continued so during the entire dyeing process. It was estimated that this sample of dyed yarn was 40% brighter than any other except No. 3, which was almost.

as bright. In order to produce such a bright color by the use of other assistants in the mordant bath, it would be necessary to use a great deal more dye-stuff.

Both pyro-phosphate treated skeins were brighter than any others and had a clearer tone in the case of N0. 3 dye-stufi. The dye-stuff baths were all very well exhausted in the case of No. 3 dye-stuff. With the No. 4 dye-stuff the skeins from the pyrophosphate mordanting baths were brighter assistant such as sulphuric acid. The result of this test was as expected and in the, case of No. 5 the better colors were roduced with the skein from No; 1 mordanting bath.

I claim therefore, broadly, tlie newly 'dis covered property of a phosphate, and particularl pyro-phosphate, 'w'hich makes it desirab e as an improved assistin agent for sodipm bi-chromate in bottom 0 oming of woo I claim as new and desire to secure by Letters Patent, is

Having thus described my invention, what 1. A mordanting bath for the bottom chroming of wool, comprising a bi-chromate of soda solution and a pyro-phosphate.

2. A mordanting bath for the bottom' chroming of wool, com rising a bi-chromate solution and a water so uble yrohosphate.

3. A mordanting bath or t e bottom chroming of wool, comprising 'a bi-chromate solution and sodium acid pyro-phosphate.

4.- A mordanting bath for the bottom chroming of wool, having sodium acid mphosphate and sodium bisulphate ded thereto.

5. Theimproved rocess for the bottom chroming of wool, w ich consists in adding sodium acid pyro-phosphate tothe mordantingbath, then Sub ecting the wool to the depositing action of the reduced chromium oxides, then washing the wool, then subjecting the wool to the action of the dye-stuff in the dye bath. v

6. The improved process for the bottom chroming of wool, which consists in adding pyro-phosphate to the mordanting bath,

then subjecting the wool to the depositing action of the reduced chromium oxide, then washing the wool, then subjecting the wool to the action of the dye-stuff of the dye bath.

7. The improved process for the bottom chroming of wool, which consists in addin as an assistant in a: mordanting bath sodlum acid pyro-phosphate and a salt capable of convertmg said pyro-phosphate'to pyrophosphoric acid in the mordanting bath.

8.. The improvement in the bottom chroming of wool, which consists in adding pyrophosphoric acid as an assistant to the mordanting bath, then subjecting the wool to the depositing action of the reduced chro- I 9. The method of assisting the action of 11. The method of assisting the action of the bichromate of a mordanting bath for the bi-chromate of a' mordanting bath for 10 bottom chroming which includes adding a bottom chroming which includes adding sopyro-phosphate to the ohromate solution. dium acid pyro-phosphate to the ohromate 10. The method of assisting the action of solution. the bichromate of a mordanting bath for In testimony whereof I afiix my signature. bottom chromin by the use of a water soluble pyro-phosp ate. 7 NEIL NEVILLE. 

